Injectable and topical neurotoxins in dermatology: Indications, adverse events, and controversies

Complications of toxins and fillers in facial aesthetics

Dermal filler and botulinum toxin injections are among the most performed non-invasive procedures for rejuvenation and contouring, internationally. Although most dermal fillers and approved botulinum toxins are well tolerated with a high safety profile, adverse events and/or complications can happen. Injection-related sequelae and side effects are usually rare, mild, transient, and self-limiting in nature. However, devastating and life-changing complications, such as intravascular occlusion, skin necrosis, permanent visual impairment, and stroke, have been reported. Risk reduction measures include an in-depth knowledge of anatomy, physiology, and pharmacology, correct patient selection, correct identification of clinical indications, and, fundamentally, the importance of appropriate skill and training. In this paper, some of the complications are discussed and advice on how to minimise adverse events and complications from these injectables is provided.

Developing Consensus-Based Guidelines for Case Reporting in Aesthetic Medicine: Enhancing Transparency and Standardization

Clinical case reporting plays a vital role in sharing detailed patient narratives, providing insights into rare conditions, innovative treatments, and unexpected outcomes. However, existing reporting guidelines in aesthetic medicine fail to capture the specific nuances of procedures and outcomes in this field. The authors' objectives were to develop comprehensive guidelines for Case REporting in Aesthetic Medicine (CREAM). The study employed a 3-phase consensus process, including a literature review, expert interviews, and a consensus meeting. A diverse group of 10 expert participants (plastic surgeons, dermatologists, noncore specialists, evidence-based medicine expert, and research scientist) in Phase I and 30 experienced aesthetic practitioners in Phase II contributed to the research. Statistical analysis was conducted to assess agreement levels among participants and explore associations and variations within the data. The participants represented various specialties, genders, LGBTQ+ identities, and ethnic backgrounds. The research resulted in the development of the CREAM guidelines, consisting of a 16-item checklist. The guidelines covered essential aspects of case reporting, such as patient and practice information, procedure details, clinical assessment and outcomes, adverse events, and ethical considerations. Statistical analysis indicated a high level of consensus among participants, as well as significant associations between checklist items. CREAM guidelines represent a step toward enhancing transparency and standardization in case reporting in aesthetic medicine. Adhering to these guidelines will allow authors to contribute to a robust evidence base, prioritize patient safety, and drive advancements aesthetic medicine.

Fabrication, characterization and evaluation of a new designed botulinum toxin-cell penetrating peptide nanoparticulate complex

BACKGROUND

To have a better and longer effect, botulinum neurotoxin (BoNT) is injected several times in a treatment course, which could increase side effects and cost. Some of the most cutting-edge strategies being investigated for proteins to their physiologic targets involve the reformulation of BoNT based on peptide-based delivery systems. For this purpose, cell-penetrating peptides (CPPs) are of particular interest because of their capacity to cross the biological membranes.

OBJECTIVES

A short and simple CPP sequence was used as a carrier to create nanocomplex particles from BoNT/A, with the purpose of increasing toxin entrapment by target cells, reducing diffusion, and increasing the duration of the effect.

METHOD

CPP-BoNT/A nanocomplexes were formed by polyelectrolyte complex (PEC) method, considering the anionic structure of botulinum toxin and the cationic CPP sequence. The cellular toxicity, and absorption profile of the complex nanoparticles were evaluated, and the digit abduction score (DAS) was used to assess the local muscle weakening efficacy of BoNT/A and CPP-BoNT/A.

RESULTS

The provided optimized polyelectrolyte complex nanoparticles had a 244 ± 20 nm particle size and 0.28 ± 0.04 PdI. In cellular toxicity, CPP-BoNT/A nanocomplexes as extended-release formulations of BoNT/A showed that nanocomplexes had a more toxic effect than BoNT/A. Furthermore, the comparison of weakening effectiveness on muscle was done among nanoparticles and free toxin on mice based on the digit abduction score (DAS) method, and nanocomplexes had a slower onset effect and a longer duration of action than toxin.

CONCLUSION

Using PEC method allowed us to form nanocomplex from proteins, and peptides without a covalent bond and harsh conditions. The muscle-weakening effect of toxin in CPP-BoNT/A nanocomplexes showed acceptable efficacy and extended-release pattern.

Efficacy and Safety of Botulinum Toxin in Adults with Raynaud's Phenomenon Secondary to Systemic Sclerosis: A Multicenter, Randomized, Double-Blind, Placebo-Controlled Study

OBJECTIVE

To determine whether a single session of botulinum toxin type A (BTA) injections into both hands more effectively decreases the frequency of systemic sclerosis-associated Raynaud's phenomenon (SSc-RP) episodes than placebo.

METHODS

This multicenter, randomized, double-blind, placebo-controlled, parallel-group phase III trial in patients with SSc-RP assessed the effect of 50-unit BTA or placebo injections into the palms of both hands around each neurovascular bundle during 1 session in winter. The primary end point was the between-group difference in the median change in the number of RP episodes from baseline (day 0) to 4 weeks postinjection. Values between the groups were compared with the Wilcoxon rank-sum test.

RESULTS

The intent-to-treat analysis included 46 BTA-treated patients and 44 placebo recipients. At 4 weeks after assigned treatment injections, the median number of daily RP episodes decreased comparably in the BTA and placebo groups (median change -1 episode/day [interquartile range (IQR) -1.5, 0 episodes/day] and -1 episode/day [IQR -2.5, 0 episodes/day], respectively) (P = 0.77 versus placebo). Moreover, change in Raynaud's Condition Score, quality of life assessed by Health Assessment Questionnaire disability index, and hand function assessed by shortened Disabilities of the Arm, Shoulder, and Hand (QuickDASH) and Cochin Hand Function Scale from baseline to follow-up weeks 4, 12, and 24 did not differ significantly between groups. The BTA group experienced transient hand muscle weakness significantly more frequently (P = 0.003).

CONCLUSION

Neither the primary nor secondary end points were reached, and our results do not support any beneficial effect of palmar BTA injections to treat SSc-RP.

Causes of Botulinum Toxin Treatment Failure

Purpose

The purpose of this article is to review the cause of botulinum toxin (BT) failure and determine the ways to minimize the risks of its occurrence.

Methods

A PubMed and Google Scholar literature search was conducted with the search terms botulinum toxin, treatment, failure, causes, and prevention. Fifteen relevant articles were found and used as the scientific base for this article.

Results

The failure of BT therapy is associated with immunogenic and non-immunogenic causes and the formation of neutralizing antibodies toward the active components of BT or the complexing proteins. Enzyme-linked immunosorbent assay (ELISA) testing and mouse hemidiaphragm assay (MHA) can diagnose the failure. The risk of developing treatment failure can be minimized by using complexing protein-free formulations, selecting a treatment regimen with the least immunogenicity, proper injection technique, and gentle product handling.

Conclusion

The treatment failure can compromise the success of BT treatment. Current medical literature shows controversial evidence for and against BT immunogenicity. Therefore, the cause of BT failure is likely to be multifactorial.

The Air Toxin Technique: Introduction and Analysis of Effect using a Photo Imaging System

BACKGROUND

As an alternative to other approaches to facial rejuvenation, the air toxin technique (dermal injection of air with micro-doses of botulinum toxin) is a promising method. We aimed to describe this novel technique and assess the overall safety and efficacy of the air toxin technique in facial rejuvenation.

MATERIALS AND METHODS

A retrospective chart review was performed on cases treated with the air toxin technique. A total of 47 Korean patients underwent a single treatment session. Treatment efficacy was assessed objectively with serial VISIA® (Canfield Scientific, NJ, USA) skin analysis data and subjectively based on the patients' assessment scores at week 12.

RESULTS

A significant improvement in Wrinkle (p < 0.001), UV spot (p < 0.001), and Porphyrin (p = 0.005) were objectively seen at 12-weeks follow-up. Patients noted improvement in the categories Wrinkle (p < 0.01), Redness (p = 0.029), Texture (p < 0.001), Dilated pore (p < 0.001), and Lifting (p < 0.001) at week 12 compared to baseline. No major adverse event was reported.

CONCLUSIONS

Our data show that the Air toxin technique is efficacious in facial rejuvenation as shown by improved skin analysis parameters and patient assessment scores. Notably, there was some discrepancy between the objective and subjective parameters of improvement.

Forehead Movement Discrepancies After Botulinum Toxin Injections: A Review of Etiology, Correction, and Prevention

BACKGROUND

Forehead rhytides are a popular target for botulinum toxin injections, but neuromodulation of the frontalis can be fraught with complications because of its anatomic complexity and integral role in brow position and expressivity.

OBJECTIVE

This article explores common forehead movement discrepancies that can occur after neuromodulation of the frontalis, as well as how to correct and prevent them.

METHODS

A review of the literature was conducted and combined with clinical experience to examine underlying forehead anatomy, etiology and correction of forehead movement discrepancies, and important factors to consider before injecting the frontalis with botulinum toxin.

RESULTS AND CONCLUSION

Variable anatomy from person to person necessitates an individualized treatment approach to achieve the best cosmetic results and prevent the occurrence of forehead movement discrepancies.

Quality and Reliability of YouTube for Patient Information on Neurotoxins

YouTube is a common source of medical information for patients. This is the first study to assess the reliability and educational value of YouTube videos on neurotoxin procedures. YouTube.com was searched on June 15, 2020 using the keyword "Botox" or "neurotoxin." A total of 100 videos were reviewed. Sixty-one videos met the inclusion criteria and were included in the final analysis. Video characteristics were noted, and a score was assigned to each video using the Journal of the American Medical Association (JAMA) benchmark criteria and the Global Quality Score (GQS) to measure source reliability and educational value, respectively. A total of 61 videos that met the inclusion criteria had an average length of 589 seconds (9 minutes and 49 seconds), 210,673 views, 5,295 likes, 318 dislikes, and 478 comments. A total of 30 videos (49%) were posted with an intention to educate patients while 31 videos (51%) were posted with the intention to detail a personal experience with neurotoxin. Patient education videos were significantly more reliable (P _JAMA< 0.001) and had more educational value (P _GQS < 0.001) but were less popular than "personal experience videos." Personal-experience videos posted by patients had higher popularity, more likes and comments, yet lower scores on reliability and education. Patients will continue to seek educational material online, and clinicians should utilize this information to help primarily educate patients with standardized and accurate information about their treatment. KEY POINTS: · Question: Are YouTube videos pertaining to neurotoxin reliable and contain useful information to educate patients to make informed decisions about their neurotoxin treatment?. · Findings: Roughly half of videos reviewed were vlogs (video logs), which were of low quality and educational value, but were more popular compared with videos that were intended to educate patients on neurotoxin treatment.. · Meaning: Patients who use YouTube as a source of information about neurotoxin treatment may be misled with inaccurate and unreliable information. Physicians must be aware of these findings to properly educate patients with standardized and accurate information about their treatment..

Facial aesthetic injections in clinical practice: Pretreatment and posttreatment consensus recommendations to minimise adverse outcomes

Facial aesthetic treatment with injectable neuromodulators and hyaluronic acid fillers is well established, with favourable safety profiles and consistent outcomes. As with any medical treatment, adverse events and complications may occur. Adverse events associated with these products are typically transient and mild to moderate in severity. Serious adverse events, such as infection and intravascular occlusion, are rare. Proper patient selection, consent and counselling, preparation and impeccable injection technique are important risk reduction strategies. Both clinicians and patients must be alert to the signs and symptoms of complications so that appropriate treatment can be started promptly. In this article, the authors review the current literature and provide their consensus recommendations for minimising adverse outcomes when treating patients with botulinum toxin or hyaluronic acid fillers.

AbobotulinumtoxinA (Dysport®), OnabotulinumtoxinA (Botox®), and IncobotulinumtoxinA (Xeomin®) Neurotoxin Content and Potential Implications for Duration of Response in Patients

Botulinum neurotoxin type-A (BoNT-A) blocks the release of acetylcholine from peripheral cholinergic nerve terminals and is an important option for the treatment of disorders characterised by excessive cholinergic neuronal activity. Several BoNT-A products are currently marketed, each with unique manufacturing processes, excipients, formulation, and non-interchangeable potency units. Nevertheless, the effects of all the products are mediated by the 150 kDa BoNT-A neurotoxin. We assessed the quantity and light chain (LC) activity of BoNT-A in three commercial BoNT-A products (Dysport^®; Botox^®; Xeomin^®). We quantified 150 kDa BoNT-A by sandwich ELISA and assessed LC activity by EndoPep assay. In both assays, we assessed the results for the commercial products against recombinant 150 kDa BoNT-A. The mean 150 kDa BoNT-A content per vial measured by ELISA was 2.69 ng/500 U vial Dysport^®, 0.90 ng/100 U vial Botox^®, and 0.40 ng/100 U vial Xeomin^®. To present clinically relevant results, we calculated the 150 kDa BoNT-A/US Food and Drug Administration (FDA)-approved dose in adult upper limb spasticity: 5.38 ng Dysport^® (1000 U; 2 × 500 U vials), 3.60 ng Botox^® (400 U; 4 × 100 U vials), and 1.61 ng Xeomin^® (400 U; 4 × 100 U vials). EndoPep assay showed similar LC activity among BoNT-A products. Thus, greater amounts of active neurotoxin are injected with Dysport^®, at FDA-approved doses, than with other products. This fact might explain the long duration of action reported across multiple indications, which benefits patients, caregivers, clinicians, and healthcare systems.

The non-neuronal and nonmuscular effects of botulinum toxin: an opportunity for a deadly molecule to treat disease in the skin and beyond

There is growing evidence that botulinum neurotoxins (BoNTs) exhibit biological effects on various human cell types with a host of associated clinical implications. This review aims to provide an update on the non-neuronal and nonmuscular effects of botulinum toxin. We critically analysed recent reports on the structure and function of cellular signalling systems subserving biological effects of BoNTs. The BoNT receptors and intracellular targets are not unique for neurotransmission. They have been found in both neuronal and non-neuronal cells, but there are differences in how BoNT binds to, and acts on, neuronal vs. non-neuronal cells. The non-neuronal cells that express one or more BoNT/A-binding proteins, and/or cleavage target synaptosomal-associated protein 25, include: epidermal keratinocytes; mesenchymal stem cells from subcutaneous adipose; nasal mucosal cells; urothelial cells; intestinal, prostate and alveolar epithelial cells; breast cell lines; neutrophils; and macrophages. Serotype BoNT/A can also elicit specific biological effects in dermal fibroblasts, sebocytes and vascular endothelial cells. Nontraditional applications of BoNT have been reported for the treatment of the following dermatological conditions: hyperhidrosis, Hailey-Hailey disease, Darier disease, inversed psoriasis, aquagenic palmoplantar keratoderma, pachyonychia congenita, multiple eccrine hydrocystomas, eccrine angiomatous hamartoma, eccrine sweat gland naevi, congenital eccrine naevus, Raynaud phenomenon and cutaneous leiomyomas. Experimental studies have demonstrated the ability of BoNT/A to protect skin flaps, facilitate wound healing, decrease thickness of hypertrophic scars, produce an anti-ageing effect, improve a mouse model of psoriasiform dermatitis, and have also revealed extracutaneous effects of BoNT arising from its anti-inflammatory and anticancer properties. BoNTs have a much wider range of applications than originally understood, and the individual cellular responses to the cholinergic impacts of BoNTs could provide fertile ground for future studies.

Ultrasound Guidance for Botulinum Neurotoxin Chemodenervation Procedures

Injections of botulinum neurotoxins (BoNTs) are prescribed by clinicians for a variety of disorders that cause over-activity of muscles; glands; pain and other structures. Accurately targeting the structure for injection is one of the principle goals when performing BoNTs procedures. Traditionally; injections have been guided by anatomic landmarks; palpation; range of motion; electromyography or electrical stimulation. Ultrasound (US) based imaging based guidance overcomes some of the limitations of traditional techniques. US and/or US combined with traditional guidance techniques is utilized and or recommended by many expert clinicians; authors and in practice guidelines by professional academies. This article reviews the advantages and disadvantages of available guidance techniques including US as well as technical aspects of US guidance and a focused literature review related to US guidance for chemodenervation procedures including BoNTs injection.